Problem: You are given an unweighted tree with n vertices. Recall that a tree is a connected undirected graph without cycles.

Your task is to choose three distinct vertices a, b, c on this tree such that the number of edges which belong to at least one of the simple paths between a and b, b and c, or a and c is the maximum possible. See the notes section for a better understanding.

The simple path is the path that visits each vertex at most once.

Input

The first line contains one integer number n (3 ≤ n ≤ 2 ⋅ 10^5) — the number of vertices in the tree. 

Next n - 1 lines describe the edges of the tree in form a_i, b_i (1 ≤ a_i, b_i ≤ n, a_i ≠ b_i). It is guaranteed that given graph is a tree.

Output

In the first line print one integer res — the maximum number of edges which belong to at least one of the simple paths between a and b, b and c, or a and c.

In the second line print three integers a, b, c such that 1 ≤ a, b, c ≤ n and a ≠, b ≠ c, a ≠ c.

If there are several answers, you can print any.

Example

Input


8
1 2
2 3
3 4
4 5
4 6
3 7
3 8


Output


5
1 8 6

Note

The picture corresponding to the first example (and another one correct answer):

<image>

If you choose vertices 1, 5, 6 then the path between 1 and 5 consists of edges (1, 2), (2, 3), (3, 4), (4, 5), the path between 1 and 6 consists of edges (1, 2), (2, 3), (3, 4), (4, 6) and the path between 5 and 6 consists of edges (4, 5), (4, 6). The union of these paths is (1, 2), (2, 3), (3, 4), (4, 5), (4, 6) so the answer is 5. It can be shown that there is no better answer.

Solution (in JAVA):

Solution:
import java.io.*;
import java.math.BigInteger;
import java.util.*;
 
public class Main {
	public static void main(String[] args) throws IOException {
		InputStream inputStream = System.in;
		OutputStream outputStream = System.out;
		PrintWriter out = new PrintWriter(outputStream);
		InputReader in = new InputReader(inputStream);
		
//		for(int i=4;i<=4;i++) {
//			InputStream uinputStream = new FileInputStream("milkvisits.in");
//			String f = i+".in";
//			InputStream uinputStream = new FileInputStream(f);
//			InputReader in = new InputReader(uinputStream);
//			PrintWriter out = new PrintWriter(new BufferedWriter(new FileWriter("milkvisits.out")));
//		}
		Task t = new Task();
		t.solve(in, out);
		out.close();
	}	
	
	static class Task{
		public void solve(InputReader in, PrintWriter out) throws IOException {
			int n = in.nextInt();
			ArrayList<Integer>[] g = new ArrayList[n];
			for(int i=0;i<n;i++) g[i] =  new ArrayList<Integer>();
			for(int i=0;i<n-1;i++) {
				int f = in.nextInt()-1;
				int t = in.nextInt()-1;
				g[f].add(t);
				g[t].add(f);
			}
			int lvl[] = new int[n];
			int u = -1;
			int v = -1;
			int dp[][] = new int[n][2];
			int f[][] = new int[n][2];
			dfs2(0,-1,g,dp,f);
			int max = -1;
			for(int i=0;i<n;i++) {
				if(dp[i][0]+dp[i][1]>max) {
					max = dp[i][0]+dp[i][1];
					u = f[i][0]; v = f[i][1];
				}
			}
			Queue<Integer> q= new LinkedList<Integer>();
			//Dumper.print(v);
			ArrayList<Integer> tmp = new ArrayList<Integer>();
			ArrayList<Integer> nodes = new ArrayList<Integer>();
			nodes.add(u);
			dfs(u,g,-1,tmp,nodes,v);
			if(nodes.size()==n) {
				out.println(n-1);
				out.print(v+1+" "+(u+1)+" ");
				for(int i=0;i<n;i++) {
					if(i!=u&&i!=v) {
						out.println(i+1);
						break;
					}
				}
			}else {
				lvl = new int[n];
				q = new LinkedList<Integer>();
				for(int i:nodes) {
					lvl[i] = 1;
					q.add(i);
				}
				max = 0;
				int c = 0;
				while(!q.isEmpty()) {
					tmp = new ArrayList<Integer>();
					while(!q.isEmpty()) tmp.add(q.poll());
					for(int i:tmp) {
						for(int nxt:g[i]) {
							if(lvl[nxt]==0) {
								lvl[nxt] = lvl[i]+1;
								q.add(nxt);
								if(lvl[nxt]>max) {
									max = lvl[nxt];
									c = nxt;
								}
							}
						}
					}
				}
				out.println(max-1+nodes.size()-1);
				out.println(u+1+" "+(v+1)+" "+(c+1));
			}			
		}
		void dfs(int cur, ArrayList<Integer>[] g, int pre, ArrayList<Integer> tmp, ArrayList<Integer> nodes, int v) {
			if(cur==v) {
				for(int i:tmp) nodes.add(i);
				return;
			}
			for(int nxt:g[cur]) {
				if(nxt!=pre) {
					tmp.add(nxt);
					dfs(nxt,g,cur,tmp,nodes,v);
					tmp.remove(tmp.size()-1);
				}
			}
		}
		void dfs2(int cur, int pre, ArrayList<Integer>[] g, int dp[][], int f[][]) {
			if(cur!=0&&g[cur].size()==1) {
				f[cur][0] = cur;return;
			}
			for(int nxt:g[cur]) {
				if(nxt==pre) continue;
				dfs2(nxt,cur,g,dp,f);
				if(dp[nxt][0]+1>dp[cur][0]) {
					dp[cur][1] = dp[cur][0];
					dp[cur][0] = dp[nxt][0]+1;					
					f[cur][1] = f[cur][0];
					f[cur][0] = f[nxt][0];
				}else if(dp[nxt][0]+1>dp[cur][1]) {
					dp[cur][1] = dp[nxt][0]+1;
					f[cur][1] = f[nxt][0];
				}			
			}
		}
	    public int maxValueAfterReverse(int[] nums) {
	    	int n = nums.length;
	    	ArrayList<pair> arr = new ArrayList<pair>();
	    	int c = 0;
	    	for(int i=0;i<n-1;i++) {
	    		arr.add(new pair(nums[i],nums[i+1]));
	    		c+=Math.abs(nums[i+1]-nums[i]);
	    	}
	    	Collections.sort(arr);
	    	//c += Math.abs(arr.get(0).x-arr.get(n-2).x) + Math.abs(arr.get(0).y-arr.get(n-2).y);
	    	//c -= Math.abs(arr.get(0).x-arr.get(0).y) + Math.abs(arr.get(n-2).x-arr.get(n-2).y);
	    	return c;
	    }
 
		class edge {
			int f,t,len;
			public edge(int a, int b, int c) {
				f=a;t=b;len=c;
			}
		}
	
		class pair implements Comparable<pair>{
			int val,idx;
			public pair(int a, int b) {
				val = a;
				idx = b;
			}
			@Override
			public int compareTo(pair t) {
				return t.val-this.val;
			}
		}
		  
	    class sgt{
	    	sgt lt;
	    	sgt rt;
	    	int l,r;
	    	long sum, max, min, lazy;
	    	public sgt(int L, int R, int arr[]) {
	    		l=L;r=R;
	    		if(l==r-1) {
	    			sum = max = min = arr[l];
	    			lazy = 0;
	    			return;
	    		}
	    		lt = new sgt(l, l+r>>1, arr);
	    		rt = new sgt(l+r>>1, r, arr);
	    		pop_up();
	    	}
	    	void pop_up() {
	    		this.sum = lt.sum + rt.sum;
	    		this.max = Math.max(lt.max, rt.max);
	    		this.min = Math.min(lt.min, rt.min);
	    	}
	    	void push_down() {
	    		if(this.lazy!=0) {
	    			lt.sum+=lazy;
	    			rt.sum+=lazy;
	    			lt.max+=lazy;
	    			lt.min+=lazy;
	    			rt.max+=lazy;
	    			rt.min+=lazy;
	    			lt.lazy+=this.lazy;
	    			rt.lazy+=this.lazy;
	    			this.lazy = 0;
	    		}
	    	}
	    	void change(int L, int R, int v) {
	    		if(R<=l||r<=L) return;
	    		if(L<=l&&r<=R) {
	    			this.max+=v;
	    			this.min+=v;
	    			this.sum+=v*(r-l);
	    			this.lazy+=v;
	    			return;
	    		}
	    		push_down();
	    		lt.change(L, R, v);
	    		rt.change(L, R, v);
	    		pop_up();
	    	}
	    	long query_max(int L, int R) {
	    		if(L<=l&&r<=R) return this.max;
	    		if(r<=L||R<=l) return Long.MIN_VALUE;
	    		push_down();
	    		return Math.max(lt.query_max(L, R), rt.query_max(L, R));	    		
	    	}
	    	long[] query_min(int L, int R) {
	    		if(L<=l&&r<=R) return new long[] {this.min, this.l};
	    		if(r<=L||R<=l) return new long[] {Long.MAX_VALUE, 99999999};
	    		push_down();
	    		long a[] = lt.query_min(L, R);
	    		long b[] = rt.query_min(L, R);
	    		if(a[0]<b[0]) return a;
	    		else if(a[0]>b[0]) return b;
	    		else return new long[] {a[0], Math.min(a[1], b[1])};
	    		//return Math.min(lt.query_min(L, R), rt.query_min(L, R));	
	    	}
	    	long query_sum(int L, int R) {
	    		if(L<=l&&r<=R) return this.sum;
	    		if(r<=L||R<=l) return 0;
	    		push_down();
	    		return lt.query_sum(L, R) + rt.query_sum(L, R);
	    	}
	    }	   
			    	
		List<List<String>> convert(String arr[][]){
			int n = arr.length;
			List<List<String>> ret = new ArrayList<>();
			for(int i=0;i<n;i++) {
				ArrayList<String> tmp = new ArrayList<String>();
				for(int j=0;j<arr[i].length;j++) tmp.add(arr[i][j]);
				ret.add(tmp);
			}
			return ret;
		}
		
		public class TreeNode {
			int val;
			TreeNode left;
			TreeNode right;
			TreeNode(int x) { val = x; }
		}
	
		public int GCD(int a, int b) {
		   if (b==0) return a;
		   return GCD(b,a%b);
		}
		public long GCD(long a, long b) {
			   if (b==0) return a;
			   return GCD(b,a%b);
		}		
	}
	
	
    static class ArrayUtils {
        static final long seed = System.nanoTime();
        static final Random rand = new Random(seed);
 
        public static void sort(int[] a) {
            shuffle(a);
            Arrays.sort(a);
        }
 
        public static void shuffle(int[] a) {
            for (int i = 0; i < a.length; i++) {
                int j = rand.nextInt(i + 1);
                int t = a[i];
                a[i] = a[j];
                a[j] = t;
            }
        }
 
    }	
	static class BIT{
		int arr[];
		int n;
		public BIT(int a) {
			n=a;
			arr = new int[n];
		}
		int sum(int p) {
			int s=0;
			while(p>0) {
				s+=arr[p];
				p-=p&(-p);
			}
			return s;
		}
		void add(int p, int v) {
			while(p<n) {
				arr[p]+=v;
				p+=p&(-p);
			}
		}
	}
	static class DSU{
		int[] arr;
		int[] sz;
		public DSU(int n) {
			arr = new int[n];
			sz = new int[n];
			for(int i=0;i<n;i++) arr[i] = i;
			Arrays.fill(sz, 1);
		}
		public int find(int a) {
			if(arr[a]!=a) arr[a] = find(arr[a]);
			return arr[a];
		}
		public void union(int a, int b) {
			int x = find(a);
			int y = find(b);
			if(x==y) return;
			arr[y] = x;
			sz[x] += sz[y];
		}
		public int size(int x) {
			return sz[find(x)];
		}
	}	
	static class MinHeap<Key> implements Iterable<Key> {
		private int maxN;
		private int n;
		private int[] pq;
		private int[] qp;
		private Key[] keys;
		private Comparator<Key> comparator;
		
		public MinHeap(int capacity){
			if (capacity < 0) throw new IllegalArgumentException();
			this.maxN = capacity;
			n=0;
			pq = new int[maxN+1];
			qp = new int[maxN+1];
			keys = (Key[]) new Object[capacity+1];
			Arrays.fill(qp, -1);
		}
		
		public MinHeap(int capacity, Comparator<Key> c){
			if (capacity < 0) throw new IllegalArgumentException();
			this.maxN = capacity;
			n=0;
			pq = new int[maxN+1];
			qp = new int[maxN+1];
			keys = (Key[]) new Object[capacity+1];
			Arrays.fill(qp, -1);
			comparator = c;
		}			
		public boolean isEmpty()	{ return n==0; 	}
		public int size()			{ return n;		}
		public boolean contains(int i) {
	        if (i < 0 || i >= maxN) throw new IllegalArgumentException();
	        return qp[i] != -1;
		}	
		public int peekIdx() {
	        if (n == 0) throw new NoSuchElementException("Priority queue underflow");
	        return pq[1];		
		}	
		public Key peek(){
			if(isEmpty()) throw new NoSuchElementException("Priority queue underflow");
			return keys[pq[1]];
		}
		public int poll(){
			if(isEmpty()) throw new NoSuchElementException("Priority queue underflow");
			int min = pq[1];
			exch(1,n--);
			down(1);
			assert min==pq[n+1];
			qp[min] = -1;
			keys[min] = null;		
			pq[n+1] = -1;
			return min;
		}
	    public void update(int i, Key key) {
	        if (i < 0 || i >= maxN) throw new IllegalArgumentException();
	        if (!contains(i)) {
	        	this.add(i, key);
	        }else {
	        	keys[i] = key;
	        	up(qp[i]);
	        	down(qp[i]);
	        }
	    }	
		private void add(int i, Key x){
	        if (i < 0 || i >= maxN) throw new IllegalArgumentException();
	        if (contains(i)) throw new IllegalArgumentException("index is already in the priority queue");
	        n++;
	        qp[i] = n;
	        pq[n] = i;
	        keys[i] = x;
	        up(n);
		}
		private void up(int k){
			while(k>1&&less(k,k/2)){
				exch(k,k/2);
				k/=2;
			}
		}
		private void down(int k){
			while(2*k<=n){
				int j=2*k;
				if(j<n&&less(j+1,j)) j++;
				if(less(k,j)) break;
				exch(k,j);
				k=j;
			}
		}
		
		public boolean less(int i, int j){
	        if (comparator == null) {
	            return ((Comparable<Key>) keys[pq[i]]).compareTo(keys[pq[j]]) < 0;
	        }
	        else {
	            return comparator.compare(keys[pq[i]], keys[pq[j]]) < 0;
	        }
		}
 
		public void exch(int i, int j){
	        int swap = pq[i];
	        pq[i] = pq[j];
	        pq[j] = swap;
	        qp[pq[i]] = i;
	        qp[pq[j]] = j;
		}
 
		@Override
		public Iterator<Key> iterator() {
			// TODO Auto-generated method stub
			return null;
		}
	}  	
 
    private static class InputReader
    {
        private InputStream stream;
        private byte[] buf = new byte[1024];
        private int zcurChar;
        private int znumChars;
        private SpaceCharFilter filter;
 
        public InputReader(InputStream stream)
        {
            this.stream = stream;
        }
 
        public int read()
        {
            if (znumChars == -1)
                throw new InputMismatchException();
            if (zcurChar >= znumChars)
            {
            	zcurChar = 0;
                try
                {
                    znumChars = stream.read(buf);
                } catch (IOException e)
                {
                    throw new InputMismatchException();
                }
                if (znumChars <= 0)
                    return -1;
            }
            return buf[zcurChar++];
        }
 
        public int nextInt()
        {
            int c = read();
            while (isSpaceChar(c))
                c = read();
            int sgn = 1;
            if (c == '-')
            {
                sgn = -1;
                c = read();
            }
            int res = 0;
            do
            {
                if (c < '0' || c > '9')
                    throw new InputMismatchException();
                res *= 10;
                res += c - '0';
                c = read();
            } while (!isSpaceChar(c));
            return res * sgn;
        }
 
        public String nextString()
        {
            int c = read();
            while (isSpaceChar(c))
                c = read();
            StringBuilder res = new StringBuilder();
            do
            {
                res.appendCodePoint(c);
                c = read();
            } while (!isSpaceChar(c));
            return res.toString();
        }
 
        public double nextDouble()
        {
            int c = read();
            while (isSpaceChar(c))
                c = read();
            int sgn = 1;
            if (c == '-')
            {
                sgn = -1;
                c = read();
            }
            double res = 0;
            while (!isSpaceChar(c) && c != '.')
            {
                if (c == 'e' || c == 'E')
                    return res * Math.pow(10, nextInt());
                if (c < '0' || c > '9')
                    throw new InputMismatchException();
                res *= 10;
                res += c - '0';
                c = read();
            }
            if (c == '.')
            {
                c = read();
                double m = 1;
                while (!isSpaceChar(c))
                {
                    if (c == 'e' || c == 'E')
                        return res * Math.pow(10, nextInt());
                    if (c < '0' || c > '9')
                        throw new InputMismatchException();
                    m /= 10;
                    res += (c - '0') * m;
                    c = read();
                }
            }
            return res * sgn;
        }
 
        public long nextLong()
        {
            int c = read();
            while (isSpaceChar(c))
                c = read();
            int sgn = 1;
            if (c == '-')
            {
                sgn = -1;
                c = read();
            }
            long res = 0;
            do
            {
                if (c < '0' || c > '9')
                    throw new InputMismatchException();
                res *= 10;
                res += c - '0';
                c = read();
            } while (!isSpaceChar(c));
            return res * sgn;
        }
 
        public boolean isSpaceChar(int c)
        {
            if (filter != null)
                return filter.isSpaceChar(c);
            return c == ' ' || c == '\n' || c == '\r' || c == '\t' || c == -1;
        }
 
        public String next()
        {
            return nextString();
        }
 
        public interface SpaceCharFilter
        {
            public boolean isSpaceChar(int ch);
        }
        public int[] readIntArray(int n) {
            int[] ret = new int[n];
            for (int i = 0; i < n; i++) {
                ret[i] = nextInt();
            }
            return ret;
        }        
    }    
 
	static class Dumper {
		static void print_int_arr(int[] arr) {
			for (int i = 0; i < arr.length; i++) {
				System.out.print(arr[i] + " ");
			}
			System.out.println();
			System.out.println("---------------------");
		}
 
		static void print_char_arr(char[] arr) {
			for (int i = 0; i < arr.length; i++) {
				System.out.print(arr[i] + " ");
			}
			System.out.println();
			System.out.println("---------------------");
		}
 
		static void print_double_arr(double[] arr) {
			for (int i = 0; i < arr.length; i++) {
				System.out.print(arr[i] + " ");
			}
			System.out.println();
			System.out.println("---------------------");
		}
 
		static void print_2d_arr(int[][] arr, int x, int y) {
			for (int i = 0; i < x; i++) {
				for (int j = 0; j < y; j++) {
					System.out.print(arr[i][j] + " ");
				}
				System.out.println();
			}
			System.out.println();
			System.out.println("---------------------");
		}
 
		static void print_2d_arr(boolean[][] arr, int x, int y) {
			for (int i = 0; i < x; i++) {
				for (int j = 0; j < y; j++) {
					System.out.print(arr[i][j] + " ");
				}
				System.out.println();
			}
			System.out.println();
			System.out.println("---------------------");
		}
 
		static void print(Object o) {
			System.out.println(o.toString());
		}
 
		static void getc() {
			System.out.println("here");
		}
	}
}